Exactly. Kevin, you didn't get what you deserved, you got what the seller wanted to give you. That is the way feedback is set up. EBay's reasoning is exactly what they said it was. If they were to get into the evaluation of feedback, they would lose their "we're just the marketplace, not the seller" defense against a host of issues. It has nothing to do with favoring the sellers over the buyers.
By the way, as Daniel says, sellers are victimized by bullshit feedback as well. It hasn't happened to me, but I've seen it happen to others.
By far the silliest negatives I've seen are the ones with the comments: Seller didn't give me feedback. Of course, those usually result in the seller giving feedback quite promptly, so I guess they are self correcting...